1. Field
The present disclosure generally relates to the design of an optical component. More specifically, the present disclosure relates to the design of an optical component with reduced temperature sensitivity.
2. Related Art
Optical interconnects or links based on silicon photonics have the potential to alleviate inter-chip communication bottlenecks in high-performance computing systems that include multiple processor chips and memory chips. This is because, relative to electrical interconnects, optical interconnects offer significantly improved: bandwidth, density, power consumption, latency, and range.
In order to make a very low power (for example, less than 1 pJ/bit) optical interconnect, a power-efficient optical source, such as a semiconductor laser or a laser source, that is compatible with silicon-on-insulator (SOI) platforms is highly desirable. However, silicon cannot efficiently emit light because of the fundamental limitations of its indirect bandgap and relatively high free-carrier absorption. Consequently, one approach for implementing silicon lasers is to integrate discrete III-V semiconductor optical amplifiers with silicon-based optical devices in a hybrid optical source. In these approaches, the III-V semiconductor provides the optical gain (and, thus, the initial light), and the silicon-based optical device provides the cavity feedback necessary for lasing through the use of a tunable ring-resonator-based reflector.
While the availability and low-cost of silicon-based optical devices are advantageous, silicon has a relatively large thermo-optic coefficient (TOC) of 1.8·10−4 K−1, which induces a red shift (i.e., to longer wavelengths) of the optical cavity modes and the reflection peak of the reflector with increasing temperature. Because unpredictable temperature fluctuations often occur in devices integrated with power-dissipating CMOS components, the lasing wavelength and the peak-reflection wavelength need to be made independent of temperature (i.e. ‘athermal’). However, existing approaches to address this problem are often complicated and expensive. For example, these existing approaches typically involve complicated measurement and feedback loops and/or power-consuming thermal-tuning elements.
Hence, what is needed is an optical source without the problems described above.